Preheat broiler with oven rack in top position. Oil a baking sheet and arrange marshmallows in a single layer. Broil 3-4 minutes or until nicely toasted. They'll slide right off the pan with no mess. Fold marshmallows into ice cream.
Divide mixture between 6 small (about 7-oz) paper or plastic cups. Cover with plastic wrap or foil and insert a popsicle stick through it to hold in place. Freeze until firm.
For Chocolate Fudge Layer:
Whisk together milk or cream, sugar and cocoa powder until smooth in a medium saucepan. Bring to a simmer over medium-high heat, whisking to dissolve sugar. Remove from heat and add chocolate. Let stand 5 minutes then whisk vigorously until smooth. Whisk in vanilla and salt; let cool.
For Graham Cracker Crumble Layer:
Stir together ingredients in a bowl until they resemble wet sand then press them crumbs together with your fingers to make nice clumps.
Pour a layer of chocolate sauce over the frozen ice cream layer in each cup (2 1/2 to 3 tbsp per pop). Sprinkle graham crumble over top, pressing into the chocolate to adhere. Freeze until chocolate is firm, about 2 hours. Run briefly under hot water to unmold or wrap tightly with plastic wrap to store for up to a week.
You can easily double or triple this recipe for a crowd.